Zetacoin (ZET) is a decentralised open-source cryptocurrency forked from Bitcoin in 2013. Zetacoin is similar to Bitcoin, but it uses newer technologies to improve the transfer speed; zetacoins are usually received within 30 seconds, making them ideal for swift, smaller, day-to-day transactions. The second important difference is that Zetacoin is inflationary. The initial supply of 160 million zetacoins are supplemented with a further 1 million coins per year, making up for lost coins and sustaining the increasing demand for the coin. Zetacoin was not pre-mined at launch and is therefore considered as a "fair-mined" cryptocurrency. Original announcement.

DistroWatch.com - BitKey

BitKey is a FREE, Debian-based live Linux distribution designed for Bitcoin users; it comes with specialist utilities to perform highly secure air-gapped Bitcoin transactions. It contains a swiss army knife of handy Bitcoin tools that support a wide range of usage models, including a few very secure ones which would otherwise be difficult to perform. The system boots into one of the three available modes: "cold-offline" - for creating a wallet and signing transactions; "cold-online" - for watching the wallet and preparing transactions; "hot-online" - standard usage but less secure as the private keys are known to the computer which is connected to the internet.

Pooled mining is a method of generating bitcoins (and other cryptocoins) where multiple users work together by pooling their computing resources, then split the block reward according to the contributed processing power. Mining in pools began when the difficulty for bitcoin mining increased to the point where it could take years for an individual miner to generate a block. The solution was for miners to pool their resources, usually through websites designed specifically for this purpose, so they could generate blocks faster.

Bitcoin (BTC) is a consensus network that enables a new payment system and a completely digital money. It is the first decentralized peer-to-peer payment network that is powered by its users with no central authority or middlemen. From a user perspective, Bitcoin is like cash for the Internet. Bitcoin is the first implementation of a concept called "crypto-currency", suggesting the idea of a new form of money that uses cryptography to control its creation and transactions, rather than a central authority. The first Bitcoin specification and proof of concept was published in 2009 in a cryptography mailing list by Satoshi Nakamoto. Satoshi left the project in late 2010 without revealing much about himself. The community has since grown exponentially with many developers working on Bitcoin. Initial announcement.